05 950 adv. went on brutal ride, bike went down on rt. side with the tires higher than the handle bars. I couldn't lift the pig so I had to wait 10 minutes or so for the next rider to come along and help up right the 950. In the mean time I did shut of the fuel, however when I tried to start it, it was obvious the bike was flooded so I held the throttle open to clear things out and when it started it back fired thru the carb. Instantly I could tell it was running on one cylinder, at about 2500 rpm it would run on both cylinders and would pop on decal a lot but only at partial throttle openings, at complete throttle closing there was no popping.
Now I have the bike home with the air cleaner off and at idle there is NO vacuum from the front carb-at all. I can put my hand over the carb opening with no change/ill effect. If I open the throttle it will start to fire on the front cylinder but does back fire thru the carb.
OK, looks like I jumped a tooth some where. I will get it apart today and do a leak-down test and assuming I did not bend a valve, where do I start looking for the problem?

Check for any vacuum leak, such as a boot issue as mentioned. If you find nothing, pull the carbs and clean them well. You might have dislodged some trash in a bowl and stopped up your pilot/idle circuit.

__________________"I'd like to meet the joker who had the nerve to call this a road!" -- Walter Sigmann "Gravity is a very fickle mistress." -- Unknown"Throttle to the donkey!" -- Marc Coma

no vacuum leak. My leak down tester does not have a fitting small enough so this will have to wait till I can get the proper part. sure seems the cam chain jumped. Has anyone had this happened and what did your bike run like when it did? I have read here some where that you never start the bike with the throttle open cause the hydraulic tensioner is not up to psi yet. what say u-guys?

+1 on the carb boot leak.. Are you sure it didn't blew off the carb (or tore the boot)?

IMO pull & reinstall the carbs (check for cracks on the boot during this, also you should check the front carb at least - as some serious backfire could cause the slide/diaphragm to melt, and as written before it's easy to clog the idle circuit as well), and if it's still producing the problem only then check the timing.

Also you should check the vacuum ports on the manifold if they are still in place / not leaking.

If the timing chain jumped (which IMO is quite rare to happen), then - because of the cams are gear driven - both intake and exhaust cams will be off, and you will probably need a degree wheel to readjust it properly.. Should this be the case, play attention to get it right (infos about firing order and proper crank degrees are on ktm950.info) - don't configure it for a bigbang setup:)

checked all the points of vacuum, even put the carbs back on with out the air box because it is difficult to see all around the boots. One weird thing is the slide on the back cylinder (the only one running at idle) flutters, a lot! it moves up and down rapidly 1/4 an inch. I know crank case air moves this way but.....?

just did a leak down test and the front cylinder will not hold any psi. I even loosened the cam towers in case the valves got tight on me and the cam was pushing down on the buckets w/out lobe contact. When blowing air into the cylinder I can feel air coming out of the intake. Burnt or bent valves????

just did a leak down test and the front cylinder will not hold any psi. I even loosened the cam towers in case the valves got tight on me and the cam was pushing down on the buckets w/out lobe contact. When blowing air into the cylinder I can feel air coming out of the intake. Burnt or bent valves????

Yes.

__________________
"Dad, can I get a motorcycle when I grow up?"
"Son, you can't do both"

Is it possible to skip the chain on the cam gears if you start the engine with the throttle open(flooded) and the hydraulic tensioner does not have a stiffie yet? I know the "what" now just trying to figure out the "why". And also does anybody have a line on valves or do stick with OEM?